Especially when the "prediction" part isn't even part of the product, it is an accidental byproduct. No one pays for access to the predictions.

And they aren't predictions, they are more like "outcome-shaping" markets, since the more liquidity that gets dumped on a particular outcome, the more motivation there is to tamper with the real-world outcome, and at a certain point it will just always happen if it is billions of dollars.

The higher the liquidity involved, the less likely the real world outcome ends up being the same as it would have been if the prediction market had never existed. Very messy.